Reading the BOG, I found the recommendation to enable APIC when running e.g. Windows XP. However the following text confuses me, and even scares me a little: "Please note that if you have earlier installed Windows XP with ACPI enabled in the BIOS, Windows XP will no longer boot up if ACPI is disabled in the BIOS. You will need to reinstall Windows XP". Does this mean that-when I now enable APIC- I run the risk that I can not boot up anymore when I disable it later, for instance when there will be problems with sound etc. ? If so, does that also mean that I have to do a complete fresh install of Windows XP, complete with all my applications ?